The listed price was so good (but really in retrospect, I should have negotiated), I just paid it.

In retrospect, it would have been easier to refiance using private/hard money even though I would pay a little more for it. 

I have had Medicaid question the sale of a house retrospectively, questioning the sale price because we bought below FMV, however, a letter explaining the price based on the “as is” condition of the house and the expenses required for renovate to get the house to FMV was sufficient.

In retrospect I'd have kept the 10 Plex off and sell any Multi-family via my network.

I have house hacked for a year and in retrospect, I paid too much for the property. 

Impressive at the time, but a loveboat-esque in retrospect.

@Matt Motil gave an excellent analogy about the crabs.In retrospect, the fact of the matter is that it's good for you to be able to share those experiences with this community which embraces your REI mindset.

In retrospect, I would have preferred to not claim these expenses against my income and simply pay the higher tax bill, than to get a tax deduction and reduce my mortgage qualification amount by a decent amount.  

But in retrospect I can put in 15 bids in 30 mins, which is a lot more be said than a regular MLS contract.

In retrospect I wish I had, because there's not a lot of sweat equity to be added at this point.